Garb and Decoration in Animals

We are not alone to wear make-up and decorate ourselves

Narcissus fell in love with his mirror image and, so the myth tells us, was transformed into a flower. We humans (note the non-sexist general term “humans”) spend an inordinate amount of time looking into mirrors, donning attractive outfits, covering pimples with make-up, wearing perfumes, and doing all sorts of things to enhance our appearance. Where did this vanity come from? Are there animals decorating themselves and wearing make-up? —>—>

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Smell : Potential Burglars Beware of dogs !

Dogs are after you !

Although most humans have a relatively big nose right in the centre of their face, that organ’s main function seem to be there to support the spectacles and to pre-warm the air that enters the nostrils. Our sense of smell isn’t exactly great when it comes to a showdown with other nose-possessing organisms, but when I use the plural “we”, I am not exactly accurate, for female noses consistently outperform those of males and there are even odours that men and children cannot but mature women can smell. There is also the aspect that in women odour thresholds vary over the menstrual cycle. Generally speaking, however, we humans aren’t smell champions and find it hard to understand how a police dog can follow the track of a wrongdoer or a lost person, how salmons sniff out their home rivers on their migrations to their birth stream, how ants smell odour trails laid down by worker ants and how male moths can possibly detect the scent of a female 10 km away.

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Something’s in the air

And it doesn’t smell too good

A good friend of mine is a doctor on a cruise ship and he could tell you a thing or two about the behaviour and the diseases of seamen and tourists, but that’s not what I want to write about. This good doctor friend of mine claimed he could identify illnesses simply by what he smells when entering a patient’s room. Sniffing at a sick person’s clothes, bed sheets or ears would give him further valuable clues, he said. And in this way he’d be able to diagnose, with his nose, stomach, liver and bladder anomalies as well as various other ailments ranging from the common cold to diabetes and even some forms of cancer.

Under normal circumstances a healthy adult contains about 150 ml (about a tea cup full) of gas at any one time in the gut. That gas is a mixture of CO2, methane, and minor foul-smelling components. This gas mixture is actually a potent greenhouse gas and it takes little imagination to think of the effects that the world’s farmed cattle population, estimated to be around 1,500,000,000 heads, has with regard to gas emissions and global climate change!

But back to us humans. Over a single day a person releases approximately 600-1,200 ml of the gas mixture mentioned above, most of it in a little-polite way through the rear end of his or her body. Some gas, however, makes its way up via the stomach to the mouth and another component is carried by the blood from the gut to the lungs, where it is breathed out in the normal way. Sweat can also be involved in releasing odours. Although some gas stems from swallowing, the majority of it is actually produced by gut microorganisms and represents breakdown products of mainly non-digestible carbohydrates in the food that a person has ingested. Everybody, and especially children all over the world, know that legumes and cabbage are very potent food in this regard (but let me tell you cherries can work quite well, too).

Anyway, if the composition of these gut organisms is disturbed through diseases or poisons, the composition and chemical natures of the gases produced inside our intestine also changes. Someone with a trained nose, like my ship’s doctor friend, can then indeed diagnose certain disorders from the odour a patient emits. That this ability can have embarrassing side effects is clear: when my friend met our captain’s wife for the first time and had exchanged a few words with her, he suddenly uttered, audible to everyone around: “Your exterior is delightful, madam, but inside there’s something rotten and you had better have your liver checked.”

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Do you smell the Autumn? Click here for reading “Autumn colors”

© Dr V.B. Meyer-Rochow and, 2016.
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